1. Field of the Invention
The present invention relates to a chip having a driving integrated circuit, and especially a chip suitable for chip on glass (COG) technology.
2. Description of the Prior Art
In COG packing techniques, a driving chip is directly disposed on a glass substrate of a display device to output a needed voltage or a signal to pixels of the display device. Accordingly, the driving chip can control the direction of liquid crystal molecules, and can therefore control the displayed colors in each pixel of the display device. The driving chip can also be called a driving integrated circuit (driving IC), since the driving chip usually uses an integrated circuit therein for working. In a COG process, the driving chip and the bottom glass substrate of the display device are directly connected by an anisotropic conductive film (ACF) or a non-conductive film (NCF), so that input/output bumps of the driving chip can be electrically connected to the metal traces of the bottom glass substrate.
ACF generally consists of non-conductive glue and conductive particles mixed in the non-conductive glue. ACF can affix the driving chip to the glass substrate, and also fill gaps formed between the bumps and the metal traces for adhering, supporting and electrically connecting the driving chip and the bottom glass substrate. However, the cost of the display device fabricated by ACF process cannot be effectively decreased, due to the large expense of the conductive particles. If NCF is directly adopted to connect most kinds of drive chips and the glass substrate of the display device, bad indentations occur in the bumps of the driving chip, leading to a poor electronic connection and even a poor display image of the display device. This is because the NCF is not electrically conductive, so the NCF is unsuitable for filling the gaps formed between the bumps and the metal traces, and it is best that there are no gaps between the bumps and the metal traces. As a result, the NCF process cannot be applied to all kinds of drive chips.